In a manufacturing process of a semiconductor device, a temperature of a semiconductor wafer as a processing target object is one of important factors that determine a characteristic of the semiconductor device. Thus, in the manufacturing process, the temperature of the semiconductor wafer needs to be controlled with high precision. Further, in the manufacturing process, there may be generated a non-uniform temperature distribution on the semiconductor wafer due to such factors as a temperature or a pressure of a processing gas, a flow of the processing gas, and the like. The non-uniform temperature distribution of the semiconductor wafer may result in generation of non-uniformity in the characteristic of the semiconductor device which is manufactured by using the processed semiconductor wafer.
To suppress this problem, there has been proposed a technique in which a distance between a semiconductor wafer and a heating stage provided at a rear surface side of the semiconductor wafer is adjusted by controlling, for example, a protruding amount of supporting pins configured to support the semiconductor wafer, so that a temperature distribution of the semiconductor wafer is controlled (see, for example, Patent Document 1). Further, there is also known a technique in which a mounting surface for a semiconductor wafer is divided into multiple heating areas, a temperature of a surface of the semiconductor wafer is measured from above the semiconductor wafer by using a thermography unit, and temperatures of the heating areas are individually controlled such that an average temperature of each heating area reaches a target temperature (see, for example, Patent Document 2).
Patent Document 1: Japanese Patent Laid-open Publication No. H06-177141
Patent Document 2: Japanese Patent Laid-open Publication No. 2009-238773
In the technique of controlling the temperature distribution of the semiconductor wafer by adjusting the protruding amount of the supporting pins, however, although it is possible to suppress the non-uniform temperature distribution of the semiconductor wafer, the effect is very limiting. Further, in the technique of controlling the temperatures of the heating areas individually such that the average temperature of each heating area becomes equal to the target temperature based on the temperature of the surface of the semiconductor wafer measured by the thermography unit, although the average temperature of each heating area can be controlled to reach the target temperature, the non-uniformity in the temperature distribution on the semiconductor wafer may not necessarily be decreased but rather increased.